Specific polyclonal antisera in rabbits against synthetic peptides from the mature region and latency associated protein (LAP) region of TGF-betas 1 through 5, alternative spliced TGF-beta2 LAP and the TGF-beta1 "modulator" associated protein have been developed. These antisera have a broad spectrum of specificities and are useful in one or more of the following assays for TGF-betas: Western immunoblots, immunoprecipitation of metabolically labeled material, radioimmunoassays, and immunohistochemical staining. However, none of these antibodies are useful in neutralization of TGF-beta bioactivity. With the recent availability of purified recombinant chicken TGF-beta3 (rcTGF-beta3), reactivity patterns of previously generated antibodies against TGF-beta peptides have been characterized on Western blots. An antibody to amino acids 50-60 of TGF-beta3 react with purified rcTGF-beta3, but not with porcine TGF-betas (pTGF-betas) 1 and 2. We have also developed polyclonal antisera against native pTGF-betas 1 and 2 in rabbits and turkeys and against rcTGF-beta3 in rabbits. Antisera against pTGF-betas 1 and 2 generated in both species were proven useful in neutralizing the biological activity of TGF-betas 1 and 2, and collectively have allowed the specific detection and/or quantitation of TGF-beta1 and TGF-beta2 by radioimmunoassays, Western immunoblots, immunoprecipitation of metabolically labeled material, radioreceptor assays, growth inhibition assays and sandwich enzyme- linked immunosorbent assays, but not immunohistochemical staining of TGF-betas. Although antisera generated against native rcTGF- beta3 neutralized the biological activity of rcTG-beta3 and immunoprecipitated (125)I-rcTGF-beta3, anti-rcTGF-beta3 was unable to neutralize TGF-beta3 secreted by rat skeletal myotubes and neonatal cardiac myocytes. Among the various mentioned assays for quantitation of TGF-betas 1 and 2 the SELISAs are the method of choice for specific, sensitive, precise and rapid measurements of TGF-betas 1 and 2 in biological fluids. The development of a SELISA for TGF-beta3 using antibodies against native rcTGF-beta3 is in progress.